Optical links are used for network communications requiring low packet jitter. For example, optical links are used in front-haul networks of wireless communication systems.
In a wireless communication system, a radio access network connects a mobile device (e.g. a User Equipment (UE) or other such device) to a core network. Different generations of wireless networks use different architectures for their core networks (e.g. the Packet Core (PC) network and the Evolved Packet Core (EPC) network as specified by the 3rd Generation Partnership Project (3GPP)). Examples of radio access networks include Global System for Mobile Communications (GSM) networks, Universal Mobile Telecommunications System (UMTS) networks, 4G Long-Term Evolution networks, and the like. A radio access network serves a geographical region and provides radio access to mobile devices through radio base stations. Examples of a radio base station include a base transceiver station (BTS), a Node B, and an Evolved Node B (eNB). A radio base station communicates with equipment mobile device within its service area by way of an air interface, and provides access to the core networks. Those skilled in the art will appreciate that in referring to a mobile device, it should be understood that the mobile device is a device that connects to a mobile network, such as a wireless network, regardless of whether the device itself is mobile.
A radio base station may have a distributed architecture. For example, a radio base station may be divided into a radio equipment controller and one or more radio equipment (also referred to as a remote radio head (RRH)). The radio equipment controller may communicate with one or more radio equipment, e.g., messages for controlling antenna transmissions at the radio equipment, by way of an interface internal to the radio base station. An example of such an internal interface is the Common Public Radio Interface (CPRI), as defined in CPRI Specification V6.0. Such an internal interface allows radio equipment and a radio equipment controller to be located remotely from one another. For example, the radio equipment may be located at an antenna site, while the radio equipment controller may be located in a data centre.
Communication by way of a CPRI interface has tight bounds on jitter, which may be satisfied by an optical link. However, such optical links may be expensive, and are not always available. There has been work on the use of CPRI over an Ethernet connection (CPRI-over-Ethernet), but much of this work has been focussed on the use of a dedicated Ethernet connection between the controller and an RRH. To ensure that the tight bounds on jitter and high speeds required for CPRI are met, the dedicated Ethernet connections are effectively treated as direct connections.
Accordingly, there exists a need for improved systems, devices, and methods for low-jitter communication, or at least alternatives.